Meshing causing holes in ground
 

Hi there,

I'm having some problems meshing a wheel as part of a car being modelled on a road.
The geometry of the vehicle is imported as a step file and then I'm creating an enclosure around it in the geometry mode before performing a cut. The enclosure settings don't permit the wheel to touch the bottom of the enclosure, so instead I have set it to a very small value such as 0.5mm.
This causes a problem when it comes to meshing as it means there is always a 'hole' in the ground where it doesn't put any elements. My next step was to reduce the minimum element size but this doesn't help the problem but instead puts a lot of very small elements in other places where the geometry is intricate (however these elements would be more than small enough to fit under the wheels).
Could any of you provide advice in this situation? Is there a way of allowing the wheels to be in contact with the ground?

(I'm using Ansys 13)

Regards,
Matthew

You need to define a thin cut at the interface of wheel and ground. Otherwise, the mesh on the wheel may penetrate into ground, and make a hole as you described.

How does one do this? In Designmodeler? After or before performing the Boolean subtracting the car body from the enclosure?

Meshing causing holes in ground
 

Mathew,
Common practice is to model a ‘low profile’ square or rectangle patch in the contact region between the tire and the road and Boolean subtract it. It doesn’t matter that it creates a ‘hole’ on the edge of the domain boundary.
This pad will also reduce poor element Skewness and Orthogonality in that region.